mate-bg: Fix memory leak

Fixes Clang static analyzer warning:

mate-bg.c:2764:2: warning: Potential leak of memory pointed to by 'size'
        g_queue_push_tail (parser->stack, g_strdup (name));
        ^~~~~~~~~~~~~~~~~

1 files changed, 2 insertions, 0 deletions

diff --git a/libmate-desktop/mate-bg.c b/libmate-desktop/mate-bg.c
index 6465879..bdc93ee 100644
--- a/libmate-desktop/mate-bg.c
+++ b/libmate-desktop/mate-bg.c
@@ -2760,6 +2760,8 @@ handle_start_element (GMarkupParseContext *context,
 			 strcmp (parser->stack->tail->data, "to") == 0) {
 			slide->file2 = g_slist_prepend (slide->file2, size);
 		}
+		else
+			g_free (size);
 	}
 	g_queue_push_tail (parser->stack, g_strdup (name));
 }